Magnetic structure and motor employing said magnetic structure, and driver comprising said motor

ABSTRACT

Provided is a small motor superior in weight/torque balance. A phase stator  10  and B phase stator  12  are disposed to face each other. A rotor is interpositioned between these stators. Electromagnetic coils are provided to the stators evenly in the circumferential direction. A permanent magnet is provided to the rotor evenly in the circumferential direction. The exciting polarity of the electromagnetic coil is alternately opposite, and this is the same for the permanent magnet. A signal having a prescribed frequency is input to the A phase electromagnetic coil and B phase electromagnetic coil. The rotor rotates between the stators as a result thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 10/533,651 filed May5, 2005 which is a National Stage (371) of International Application No.PCT/JP2003/014667 filed Nov. 18, 2003, and published in English asWO2004/047258 A2 on Jun. 3, 2004, which claims the benefit of JapaneseApplication Nos. 2002-334160 filed Nov. 18, 2002; 2003-157229 filed Jun.2, 2003; 2003-175456 filed Jun. 19, 2003; and 2003-313170 filed Sep. 4,2003. The disclosures of the above applications are incorporated hereinby reference.

TECHNICAL FIELD

The present invention relates to various motors for rotating a rotor ormoving a slider formed from a permanent magnet or a ferromagnetic bodyby linearly arranging a coil capable of generating a magnetic pole andsequentially switching the current to be flowed to the coil, and furtherrelates to a magnetic structure body to be employed in such a motor. Thepresent invention also relates to a driver employing this motor as adrive source. The present invention may be employed to be a driver inthe likes of an electric vehicle, electric cart, electric wheelchair, aswell as other electric toys, electric airplanes, miniature electricdevices, MEMS, and so on.

BACKGROUND ART

An AC motor driven by a frequency signal such as an alternating currentcan be broadly classified into two types; namely, a synchronous motorand an induction motor. A synchronous motor is a motor that rotates atthe same rotational speed as the speed of the rotating magnetic fielddetermined with the power supply frequency upon employing a laminatedcore of a permanent magnet or a ferromagnetic body such as iron as therotor.

Depending on the type of rotor, there is a magnet type employing apermanent magnet, a coil type in which a coil is wound thereto, and areactance type employing a ferromagnetic body such as iron. Among theabove, with the magnet type, the permanent magnet of the rotor rotatesby being pulled by the rotating magnetic field of the stator. Meanwhile,the induction motor is a motor that rotates by the conductor generatinga separate magnetic field with the electromagnetic induction effect tothe rotor shaped like a cage.

Among the foregoing motors, there are types that move linearly withoutrotating, or are able to move freely on the surface. These types ofmotors are generally referred to as linear motors, and, by linearlyarranging the coil for generating a magnetic pole and sequentiallyswitching the current to be flowed, the permanent magnet orferromagnetic body mounted thereon will move. The coil arrangementdisposed linearly corresponds to a stator, and a rotor corresponds to aflat slider that slides above such stator.

As the foregoing magnet type synchronous motor, for example, there is aminiature synchronous motor described in Japanese Patent Laid-OpenPublication No. H8-51745 (Patent Document 1). As illustrated in FIG. 1of Patent Document 1, this miniature synchronous motor is structured bycomprising a stator core 6 to which an exciting coil 7 is wound, and arotor 3 having a built-in magnet 1 and a rotor core 2 in which NS polesare disposed in equal intervals around the circumference thereof.

Nevertheless, with the motor explained in the conventional art, there isa problem in that the weight will increase in comparison to thegenerated torque, and the size thereof must be enlarged in order togenerate greater torque. Thus, an object of the present invention is toprovide a magnetic structure to be employed in a motor superior intorque and weight balance and suitable for miniaturization, a motorutilizing this structure, and a driving method of this magneticstructure. Another object of the present invention is to provide variousdrivers utilizing this motor.

SUMMARY OF THE INVENTION

As a result of intense study to overcome the foregoing problems, thepresent inventors discovered that, since the magnetic structurestructuring the (stator) and (slider, rotor) of the motor is of aone-to-one relationship with a conventional motor, the foregoingproblems can be resolved by making this a many-to-one relationship.

The present invention was devised based on the foregoing discovery, andprovided is a magnetic structure comprising a first magnetic body and asecond magnetic body, and a third magnetic body disposed therebetweenand relatively movable in a prescribed direction in relation to thefirst and second magnetic bodies, wherein the first magnetic body andsecond magnetic body respectively comprise a structure in which aplurality of electromagnetic coils capable of alternately excitingopposite poles is disposed in order; and the first magnetic body and thesecond magnetic body are structured such that an electromagnetic coil ofthe first magnetic body and an electromagnetic coil of the secondmagnetic body are disposed so as to mutually posses an array pitchdifference.

The third magnetic body comprises a structure in which a permanentmagnet alternately magnetized to opposite poles is disposed in order,and the first magnetic body and the second magnetic body are structuredsuch that a magnetic coil of the first magnetic body and a magnetic coilof the second magnetic body are disposed so as to mutually posses anarray pitch difference.

In a mode of the present invention, provided is circuit means forsupplying a frequency signal having respectively different phases to themagnetic coil of the first and second magnetic bodies. Further, thefirst magnetic body, second magnetic body and third magnetic body arerespectively formed in a circular arc. The first magnetic body, secondmagnetic body and third magnetic body may also be respectively formed ina straight line. The first magnetic body and second magnetic body aredisposed at an equidistance, and the third magnetic body is disposedbetween the first magnetic body and second magnetic body.

In a motor employing this magnetic body, the pair formed from the firstand second magnetic bodies and one side of the third magnetic body forma rotor, and the pair formed from the first and second magnetic bodiesand the other side of the third magnetic body form a stator. This motorcomprises a rotational speed detection means of the rotor. Moreover, theexciting circuit means comprises reference pulse signal generationmeans; and phase correction means for correcting the phase of theexciting current to be supplied to the electromagnetic coil of the firstmagnetic body and the electromagnetic coil of the second magnetic bodybased on the rotational speed detection signal and the reference pulsesignal. The phase difference between the exciting current supplied tothe first magnetic body and the exciting current supplied to the secondmagnetic body in accordance with the rotational position of the rotorchanges.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(1)-1(4) are views showing the frame format and operationalprinciple of the magnetic structure according to the present invention.

FIGS. 2(5)-2(8) show the operational principle subsequent to FIG. 1.

FIGS. 3(9)-3(12) show the operational principle subsequent to FIG. 2.

FIGS. 4(13)-4(16) show the operational principle subsequent to FIG. 3.

FIGS. 5(1) and 5(2) are equivalent circuit diagrams showing theconnection state of the electromagnetic coil.

FIG. 6 is a block diagram showing an example of the exciting circuit forapplying exciting current to the electromagnetic coil.

FIG. 7 is a block diagram showing the detailed structure of the driverunit of the exciting circuit.

FIGS. 8(1)-8(5) are diagrams showing the materialization of the magneticstructure as a synchronous motor, wherein FIG. 8(1) is a perspectiveview of the motor; FIG. 8(2) is a schematic plan view of the rotor; FIG.8(3) is a side view thereof; FIG. 8(4) shows the A phase electromagneticcoil (first magnetic body); and FIG. 8(5) shows the B phaseelectromagnetic coil (second magnetic body).

FIG. 9 is a view showing the frame format of the positional relationshipof the respective phase coil drive sensors in relation to the rotorcomprising a permanent magnet.

FIG. 10 is a waveform chart pertaining to the signal processing for thecoil exciting frequency signal formed in the driver.

FIG. 11 is a signal waveform when the rotor or slider is inverted.

FIG. 12 is a circuit block diagram showing another embodiment of thecoil exciting circuit.

FIG. 13 is a waveform chart pertaining to the signal processingperformed in the exciting circuit structured as illustrated in FIG. 10.

FIG. 14 is a block diagram showing the circuit structure in a case ofemploying a magnetic structure without comprising a sensor.

FIG. 15 is a waveform chart for explaining the operation of the phasecorrection in relation to the circuit structure illustrated in FIG. 14.

FIGS. 16(1)-16(7) are waveform charts in the signal processing when therotational speed of the rotor becomes high.

FIG. 17 is a detailed diagram of the A phase and B phase buffer circuitsdescribed above.

FIG. 18 is a block diagram showing another embodiment of the driver unitillustrated in FIG. 6.

FIG. 19 is a detailed block diagram of the driver unit illustrated inFIG. 6.

FIGS. 20(1) and 20(2) are PWM control waveform characteristic charts ofthe exciting current output to the coil.

FIG. 21 is a waveform characteristic chart according to the blockstructure illustrated in FIG. 19.

FIG. 22 is a waveform control characteristic chart upon inverting themotor.

FIG. 23 is a block diagram showing another embodiment of the excitingcircuit for applying exciting current to the electromagnetic coil.

FIG. 24 is a waveform chart thereof.

FIG. 25 is a block diagram showing another embodiment of the start-upcontrol unit and sensor follow-up control unit.

FIG. 26 is the control waveform chart thereof.

FIG. 27 is a block diagram showing another embodiment of the drive ofthe respective phase coils.

FIGS. 28(1)-28(4) are views showing the frame format and operationalprinciple of the second magnetic structure according to the presentinvention.

FIGS. 29(1) and 29(2) are equivalent circuit diagrams showing theconnection state of the electromagnetic coil illustrated in FIG. 28.

FIGS. 30(1)-30(5) are diagrams showing the structure of the motorpertaining to the magnetic structure illustrated in FIG. 28.

FIG. 31 is a signal waveform chart in an embodiment where two phases ofdrive signals are respectively supplied to the A phase electromagneticcoil and B phase electromagnetic coil in the functional block diagramillustrated in FIG. 6.

FIGS. 32(1) and 32(2) are block diagrams of the buffer circuitcorresponding to the waveform characteristic illustrated in FIG. 31.

FIGS. 33(1) and 33(2) are modified examples of the motor illustrated inFIG. 8, and FIG. 33(1) is the plan view thereof; and FIG. 33(2) is theside view thereof.

FIGS. 34(1)-34(4) are views showing the frame format of the linear motorformed with the magnetic structure according to the present invention.

FIG. 35 is a view showing the frame format of a motor pertaining to yetanother embodiment.

FIGS. 36(1) and 36(2) are diagrams for explaining a motor pertaining toyet another embodiment.

FIGS. 37(1) and 37(2) are modified examples of the rotor illustrated inFIG. 14.

FIGS. 38(1) and 38(2) are waveform charts showing the operation of powergeneration in a case of employing the magnetic body of the presentinvention as the power generator.

FIGS. 39(1) and 39(2) are views showing the frame format pertaining tothe structure of a motor in which the displacement of the stator formedwith the first magnetic body and the stator formed with the secondmagnetic body differs from the displacement illustrated in FIG. 33,wherein FIG. 39(1) is a plan view thereof; and FIG. 39(2) is an A-Across section thereof.

FIG. 40 is a plan view of a multipolar exciting rotor.

FIG. 41 is a conceptual diagram of the torque calculation of the rotor.

FIGS. 42(1) and 42(2) are conceptual diagrams of the drive of the rotorformed in a fan shape.

FIG. 43 is a modified example of FIG. 35.

FIG. 44 is another modified example thereof.

FIGS. 45(1) and 45(2) are application examples of applying an embodimentaccording to the present invention for driving a lens.

FIGS. 46(1) and 46(2) are diagrams showing an application exampleapplying the magnetic structure according to the present invention in acirculating body.

FIGS. 47(1)-47(3) are diagrams showing an embodiment of applying themagnetic structure according to the present invention in a flexiblecirculating body.

FIGS. 48(1)-48(3) are circuits showing the load circuit unit.

FIGS. 49(1) and 49(2) are diagrams showing the cross section structureof the case in order to indicate the surface processing of the case forhousing the magnetic structure pertaining to the present invention.

FIG. 50 is a diagram showing the power generation principle of themagnetic structure pertaining to the present invention and also showingthe detailed explanation of the magnetic structure of FIG.1-4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 to FIG. 4 are views showing the frame format and operationalprinciple of the magnetic structure according to the present invention.This magnetic structure is structured by comprising a first magneticbody (A phase coil) 10 and a second magnetic body (B phase coil) 12having a magnetic field in the horizontal direction, and a thirdmagnetic body 14 interpositioned therebetween. These magnetic bodies maybe structured circularly (circular arc, circle) or in a straight line.

When the magnetic body is formed circularly, either the third magneticbody or the first/second magnetic body functions as the rotor, and, whenthe magnetic body is formed linearly, either the third magnetic body orthe first second magnetic body functions as a slider.

The first magnetic body 10 comprises a structure in which coils 16capable of being alternately magnetized to opposite poles are disposedin order in prescribed intervals, preferably in equal intervals. Theequivalent circuit diagram of this first magnetic body is shown in FIG.5. According to FIG. 1 to FIG. 4, as described later, every coil isconstantly excited during the start-up rotation (2π) in relation to thetwo-phase exciting coil. Therefore, a drive such as a rotor or slidermay be rotated or driven at high torque.

As shown in FIG. 5(1), a plurality of electromagnetic coils 16 (magneticunits) is connected serially in equal intervals. Reference numeral 18Ais an exciting circuit block for applying a frequency pulse signal tothis magnetic coil. An exciting signal for magnetizing the coil isflowed from this exciting circuit to the electromagnetic coil 16, andthe respective coils are set in advance to magnetize such that thedirection of the magnetic pole changes alternately between the adjacentcoils. As shown in FIG. 5(2), the electromagnetic coils 16 may also beconnected in parallel.

When a signal having a frequency for alternately switching in prescribedcycles the polar direction of the exciting current to be supplied isapplied from this exciting circuit 18A to the electromagnetic coil 16 ofthe first magnetic body 10, as shown in FIG. 1 to FIG. 4, a magneticpattern is formed in which the polarity on the side of the thirdmagnetic body 14 alternately changes from the N pole→S pole→N pole. Whenthe frequency pulse signal becomes a reverse polarity, a magneticpattern is generated in which the polarity on the third magnetic bodyside of the first magnetic body alternately changes from the S pole→Npole→S pole. As a result, the exciting pattern appearing in the firstmagnetic body 10 changes periodically.

The structure of the second magnetic body 12 is similar to the firstmagnetic body 10, but differs with respect to the point in that theelectromagnetic coil 18 of the second magnetic body is disposedpositionally out of alignment in relation to the electromagnetic coil 16of the first magnetic body. In other words, as described in the claims,the array pitch of the first magnetic body coil and the array pitch ofthe second magnetic body coil are set to have a prescribed pitchdifference (angular difference). As this pitch difference, preferablyemployed may be a distance corresponding to π/2 or ¼ of the distance inwhich the permanent magnet (third magnetic body) 14 moves incorrespondence with one cycle (2π) of the exciting current frequency inrelation to the coils 16, 18; that is, the total distance of a pair of Npole and S pole.

Next, the third magnetic body 14 is explained below. As shown in FIG. 1to FIG. 4, this third magnetic body 14 is disposed between the firstmagnetic body and second magnetic body, and a plurality of permanentmagnets 20 (marked out in black) having alternately reverse polaritiesis disposed linearly (in a straight line or circular arc) in prescribedintervals, preferably in equal intervals. A circular arc may be aperfect circle, oval, closed loop, and further include an unspecifiedcircular structure, half circle, and fan shape.

The first magnetic body 10 and the second magnetic body 12 are disposedin parallel for example in an equidistance, and the third magnetic body14 is disposed in the middle of the first magnetic body and the secondmagnetic body. The array pitch of the individual permanent magnets inthe third magnetic body is approximately the same as the array pitch ofthe magnetic coil in the first magnetic body 10 and the second magneticbody 12.

Next, the operation of the magnetic structure in which the foregoingthird magnetic body 14 is disposed between the first magnetic body 10and the second magnetic body 12 is explained with reference to FIG. 1 toFIG. 4. As a result of the foregoing exciting circuit (reference numeral18 in FIG. 5; described later), an exciting pattern as shown in FIG.1(1) is generated to the electromagnetic coils 16, 18 of the firstmagnetic body and second magnetic body at a certain moment.

Here, a magnetic pole is generated in a pattern of →S→N→S→N→S→ to therespective coils 16 on the surface facing the third magnetic body 14side of the first magnetic body, and a magnetic pole is generated in apattern of →N→S→N→S→N→ to the coil 18 on the surface facing the thirdmagnetic body 14 side of the second magnetic body 12. In the diagrams,arrows displayed in a solid line represent attraction, and arrowsdisplayed in a chain line represent repulsion.

The next moment, as shown in (2), when the polarity of the wave pulseapplied to the first magnetic body via the drive circuit is inverted,repulsion is generated between the magnetic pole generated in the coil16 of the first magnetic body 10 shown in (1) and the magnetic pole ofthe permanent magnet 20 on the surface of the third magnetic body 14. Onthe other hand, attraction is generated between the magnetic polegenerated in the coil 18 of the second magnetic body 12 and the magneticpole on the surface of the permanent magnet of the third magnetic body14. Thus, the third magnetic body sequentially moves in the horizontaldirection as shown in (1) to (5).

A wave pulse having a phase out of alignment in comparison to theexciting current of the first magnetic body is applied to the coil 18 ofthe second magnetic body 12, and, as shown in (6) to (8), the magneticpole of the coil 18 of the second magnetic body 12 and the magnetic poleon the surface of the permanent magnet 20 of the third magnetic body 14repel to make the third magnetic body 14 move horizontally even further.(1) to (8) show cases when the permanent magnet moves a distancecorresponding to π, and (9) to (16) show cases when the permanent magnetmoves a distance corresponding to the remaining π. In other words, thethird magnetic body moves relatively in relation to the first and secondmagnetic bodies in a distance corresponding to one cycle (2π) of thefrequency signal supplied to the electromagnetic coils 16, 18 in (1) to(16).

As described above, by respectively supplying frequency signals havingmutually differing phases to the first magnetic body (A phase) and thesecond magnetic body (B phase), the third magnetic body 14 may be slidlinearly, or the third magnetic body 14 may be rotated as a rotor.

When the first magnetic body, second magnetic body and third magneticbody are formed in a circular arc, the magnetic structure shown in FIG.1 will become a structure of a rotating motor, and, when these magneticbodies are formed in a straight line, this magnetic structure willbecome a structure of a linear motor. Although portions other than thepermanent magnet such as the case or rotor and electromagnetic coil maybe formed from a conductor, it is preferable to form such portions froma nonmagnetic and lightweight body such as resin, aluminum or magnesiumso as to enable weight saving, and to realize a rotating driver such amotor having an open magnetic circuit and superior in magneticefficiency. The magnetic structure of the present invention does notgenerate iron loss (eddy current loss) since it is of a structure thatdoes not employ iron materials. In other words, the present inventionprovides a method, device or system for driving a moving body such as arotor or slider by switching with the likes of a control device theattraction and repulsion between an electromagnetic coil, which isformed by winding a coil around a nonmagnetic body (e.g., winding aconducting sleeve around a nonmagnetic bobbin), and a permanent magnet.In the embodiments described later, a drive device structured from anonmagnetic stator obtained by forming a coil with a nonmagnetic bobbinis explained.

Incidentally, as a result of making the coil bobbin and case fromaluminum, a superior cooling effect is yielded in that the internal heatgenerated from the copper loss can be easily conducted and released tothe outside. FIG. 49(1) is a view showing a frame format of the state ofa surface-processed case for shielding the magnetic flux leak from thecase. The case 900 is subject to copper plating 902 and steel (siliconsteel for example) plating 904, and then subject to finishing plating906. FIG. 49(2) shows a case of applying an undercoating material 903 onthe case material, thereafter applying steel (silicon steel for example)containing application material, and then applying a finishingapplication material 905.

According to this magnetic structure, since the third magnetic body willmove upon being subject to the magnetic force from the first magneticbody and second magnetic body, the torque upon moving the third magneticbody will increase, and the weight balance will become superior. Thus,it is possible to provide a miniature and lightweight motor capable ofbeing driven with a high torque.

FIG. 6 is a block diagram showing an example of the exciting circuit 18Afor applying exciting current to the electromagnetic coil (A phaseelectromagnetic coil) of the first magnetic body and the electromagneticcoil (B phase electromagnetic coil) of the second magnetic body.

This exciting circuit is structured to supply respectively controlledpulse frequency signals to the A phase electromagnetic coil 16 and the Bphase electromagnetic coil 18. Reference numeral 30 is a quartzoscillator, and reference numeral 31 is an M-PLL circuit 31 forgenerating a reference pulse signal upon M-dividing this oscillationfrequency signal.

Reference numeral 34 is a sensor for generating a position detectionsignal corresponding to the rotational speed of the third magnetic body(a rotor in this case) 14. As this sensor, a digital output method oranalog output method sensor may be used, and, for instance, a holesensor (magnetic sensor) or optical sensor may be suitably selected. Therotor is provided with holes in a number corresponding to the number ofpermanent magnets (in the case of a magnetic sensor, holes will not benecessary by providing a magnetic sensor that responds to the respectivepermanent magnets of the rotor in relation to the optical sensor unit),and, when the hole corresponds to the sensor, the sensor generates apulse each time it passes through the hole location. Reference numeral34A is an A phase side sensor for supplying a detection signal to thedriver circuit of the A phase electromagnetic coil, and referencenumeral 34B is a B phase side sensor for supplying a detection signal tothe driver circuit of the B phase electromagnetic coil.

The pulse signals from these sensors 34A, 34B are respectively output tothe driver 32 for supplying exciting current to the first and secondmagnetic bodies. Reference numeral 33 is a CPU, and outputs a prescribedcontrol signal to the M-PLL circuit 31 and the driver 32.

FIG. 7 is a block diagram showing the detailed structure of the driverunit. This driver unit is structured by comprising an A phase sidepolarity switching unit 32A, a B phase side polarity switching unit 32B,an A phase side phase correction unit 32C, a B phase side phasecorrection unit 32E, an A phase buffer 32G, a B phase buffer 32H, aD-PLL circuit 32I, and a normal rotation/reverse rotation switching unit32J.

To this driver 32 is input a fundamental wave 31 in which an oscillationfrequency was M-divided with a quartz oscillator. With this fundamentalwave, the polarity is switched with the A phase coil (first magneticbody) polarity switching unit 32A, and then input to the A phase coilphase correction unit 32C. Further, with this fundamental wave 31, thephase is controlled with the B phase coil (second magnetic body) phaseswitching unit 32B and then output to the B phase coil phase correctionunit 32E.

The control signal of the CPU 33 is output to the switching unit 32J ofthe normal rotation (forward)/reverse rotation (backward) of the rotoror slider, and the switching unit 32J controls the foregoing A phase andB phase polarity switching units 32A, 32B under the control of the CPU33 and in accordance with the normal rotation/reverse rotation.

Output from the A phase sensor 34A is output to the A phase coil phasecorrection unit 32C, and output from the B phase sensor 34B is output tothe B phase coil phase correction unit 32E. Further, the fundamentalwave output from the A phase polarity switching unit 32A and in whichthe polarity has been switched is output to the A phase correction unit,and the fundamental wave from the B phase polarity switching unit isoutput to the B phase correction unit 32E. Moreover, frequency signalsin which the fundamental wave is further multiplied at a phase-lockeddividing ratio (D) in the D-PLL circuit 32I are respectively input tothe A phase side phase correction unit 32C and the B phase side phasecorrection unit 32E.

The CPU 33 changes the frequency of the fundamental wave with thereadout value (M) by reading the M dividing ratio from a prescribedmemory in order to control the rotational speed of the rotor or thespeed of the slider, which is the third magnetic body, based on theinput information from the operation input means not shown. Further, asdescribed later, this also applies to the dividing ratio (D) of theD-PLL. These dividing ratios change in accordance with the value of theoperational characteristics of the magnetic body; for instance, therotational speed of the rotor and moving speed of the slider, and thesevariation characteristics are preset and pre-stored in a prescribedmemory area in a memory table format.

The A phase side phase correction unit 32C and the B phase side phasecorrection unit 32E correct the phases of the A phase exciting frequencysignal and B phase exciting frequency signal so as to becomesynchronized with the signals of the foregoing sensors 34A, 34B so as tooutput an exciting frequency signal in which the A phase coil and Bphase coil respectively and mutually have a suitable phase difference soas to rotate or advance the rotor or slider, which is the third magneticbody.

The A phase buffer unit 32G is a circuit means for supplying aphase-corrected frequency signal to the A phase coil, and the B phasebuffer unit 32H is a circuit means for supplying a phase-correctedfrequency signal to the B phase coil.

FIG. 8 is a diagram showing the materialization of the magneticstructure as a synchronous motor, wherein FIG. 8(1) is a perspectiveview of the motor; FIG. 8(2) is a schematic plan view of the rotor(third magnetic body); FIG. 8(3) is a side view thereof; FIG. 8(4) showsthe A phase electromagnetic coil (first magnetic body); and FIG. 8(5)shows the B phase electromagnetic coil (second magnetic body). Thereference numerals indicated in FIG. 8 are the same as the structuralcomponents corresponding to the foregoing diagrams.

This motor comprising a pair of A phase magnetic body 10 and B phasemagnetic body 12 corresponding to a stator, as well as the thirdmagnetic body 14 structuring a rotor, and the rotor 14 is disposedbetween the A phase magnetic body and the B phase magnetic body androtatably around the axis 37. In order for the rotor and rotational axisto rotate integrally, the rotational axis 37 is press fitted into arotational axis aperture. As shown in FIGS. 8(2), (4) and (5), sixpermanent magnets are provided to the rotor in equal intervals aroundthe circumferential direction thereof. Polarities of the permanentmagnets are made to be mutually opposite, and six electromagnetic coilsare provided to the stator in equal intervals around the circumferentialdirection thereof.

The A phase sensor 34A and B phase sensor 34B are provided to thesidewall inside the case of the A phase magnetic body (first magneticbody) via a specified distance T (distance corresponding to π/2).Applied to the distance between the A phase sensor 34A and B phasesensor 34B is a distance corresponding to a value for providing aprescribed phase difference to the frequency signal supplied to the Aphase coil 16 and the frequency signal supplied to the B phase coil 18.

As described above, a plurality of holes 35 (for instance, a numberequivalent to the number of permanent magnets disposed evenly around thecircumferential direction of the rotor; six holes in the presentembodiment) is formed evenly at the edge in the circumferentialdirection of the rotor formed in a circle. The sensor is structured froma light-emitting unit and a light-reception unit. A member is employedin this hole for constantly reflecting the infrared light from thelight-emitting unit of the sensor and absorbing this at the time ofdetecting the position.

Here, A phase and B phase sensors generate a pulse each time the hole 35passes through the sensor while the rotor 14 is rotating. In otherwords, a concave groove for absorbing light or a light-absorptionmaterial is provided to the hole 35, and, each time the hole passesthrough the sensor, the light-reception unit of the sensor does notreceive the light emitted from the light-emitting unit. Therefore, thesensor generates a wave pulse of a prescribed frequency in accordancewith the rotational speed of the rotor 14 and the number of holes.

FIG. 9 is a plan view of the rotor (disk) 14 comprising a permanentmagnet 20 for generating a magnetic field in the horizontal direction(circumferential direction). In the foregoing embodiments, although therespective phase sensors were formed with a combination of opticalsensors 34A, B and holes 35, magnetic sensors (MR sensors) may be usedinstead. Further, although the hole 35 was formed between magnets, thehole may also be provided to the permanent magnet portion. Here, thepositional relationship of the A phase sensor and B phase sensor must beinverted.

FIG. 10 is a waveform chart pertaining to the signal processing for thecoil exciting frequency signal formed in the driver 32. In the followingexplanation, it would be useful to refer to FIG. 8 as necessary. (1) isa reference frequency waveform, (2) is a signal from the A phase sensor34A, and (3) is a signal from the B phase sensor 34B. As describedabove, the A phase sensor and B phase sensor are installed in the motorso as to output a prescribed phase difference (π/2 in this case) (c.f.FIG. 8).

The A phase side phase correction unit 32C implements the conventionalPLL control, synchronizes the phase of the output waveform (2) of the Aphase sensor and the phase of the fundamental wave (1), and outputs awave pulse such as (4) for exciting the A phase coil 16 to the A phasecoil buffer circuit 32G. This buffer circuit structure will be describedlater.

With an input pulse having a frequency, the buffer circuit PWM-controlsa transistor in this buffer circuit for energizing exciting current tothe A phase coil. The same applies to the operation of the B phase sidephase correction unit 32E. (5) is a drive waveform output from the Bphase side phase correction unit 32E to the B phase electromagnetic coilbuffer circuit 32H. As evident upon comparing (4) and (5), phases of theexciting signal supplied to the A phase coil 16 and the exciting signalsupplied to the B phase coil 18 mutually differ, and the phasedifference is π/2.

FIG. 11 is a signal waveform when the rotor or slider is inverted. Whencomparing this waveform with the waveform illustrated in FIG. 10, thepolarity of the exciting wave pulse to be supplied to the B phaseelectromagnetic coil 18 is inverted in FIG. 11, and this is the onlydifference. FIG. 10(5) and FIG. 11(5) will now be compared. Uponswitching from FIG. 10 to FIG. 11, a brake is applied to the rotatingdirection of FIG. 10.

Next, another embodiment of the coil exciting circuit is explained withreference to FIG. 12. The point in which the circuit pertaining to thepresent embodiment differs from the circuit illustrated in FIG. 7 isthat an SA-PLL control circuit 37A for dividing and SA-multiplying thepulse signal from the A phase sensor, and, similarly, an SB-PLL controlcircuit 37A for dividing and SB-multiplying the pulse signal from the Bphase sensor are provided in order to supply the pulse signal having adivided frequency to the respective phase correction units (32C, 32E) ofthe driver 32.

This circuit is adopted when the hole 35 is provided in only onelocation to the rotor 14 of the motor (FIG. 8) described above. FIG. 13is a waveform chart pertaining to the signal processing performed in theexciting circuit structured as depicted in FIG. 12. As shown in FIG.13(2) and (3), the frequency of the detected wave output from therespective sensors of the A phase and B phase is ⅙ the case illustratedin FIG. 10. In other words, a single pulse is output each time the rotormakes a single rotation.

The frequency of the pulse waveform output from the A phase sensor ismultiplied by six in the SA-PLL 37A so as to become the waveformdepicted in (4), and the frequency of the wave pulse from the B phasesensor shown in (5) is similarly multiplied by six in the SB-PLL 37B soas to become the waveform depicted in (5).

The frequency-corrected phases of the wave pulse from the sensor andwave pulse of the fundamental wave are synchronized, and a drive signalhaving a waveform shown in FIG. 13(6) is supplied from the A phase coilphase correction unit 32C to the A phase coil buffer circuit 32G.Similarly, a drive signal having the waveform shown in (7) is suppliedfrom the B phase coil phase correction unit 32E to the B phase coilbuffer circuit 32H.

FIG. 14 is a diagram showing a drive with an open loop, without havingto use the A phase sensor 34A and B phase sensor 34B illustrated in FIG.6, by exciting the A phase electromagnetic coil and B phaseelectromagnetic coil in accordance with the frequency from the M-PLL 31,and without having to return the signal from the sensor to the driver.And, as shown in FIG. 15, drive signals having the same frequency aresupplied to the A phase electromagnetic coil and B phase electromagneticcoil having a 90-degree phase difference based on the signal from theM-PLL 31.

FIG. 16 is a waveform chart in the signal processing when the rotationalspeed of the rotor (c.f. FIG. 8) becomes high. The characteristic aspectof this processing is in that, when the rotational speed of the rotorbecomes high, in order to compensate for the influence of the inertialforce pertaining to the rotation of the rotor, the phase of the excitingcurrent is corrected to a phase of the exciting current in a case of therotational speed of the rotor is within a range where such influencedoes not exist.

Waveforms (1) to (5) are the same as the waveform characteristicsillustrated in FIG. 10. The waveforms of FIG. 10 are obtained as aresult of performing signal processing in a case of the rotational speedof the rotor is within a range where such influence does not exist. Whenthe rotational speed of the rotor becomes high, switching of theexciting polarity of the respective electromagnetic coils of the stators(10, 12) in relation to the rotation of the rotor is delayed, and arepressive influence in relation to the control request for trying toincrease the rotational speed of rotor will arise. Thus, as shown in theA phase side exciting current waveform (6), the phase has been advancedfor an H amount than the A phase side exciting current waveform (4) inthe case where the rotor is rotating a low speed or medium speed. Thisalso applies to the B phase side coil (c.f. (5) and (7)).

In order to shift the phase, the phase correction unit (32C, 32E) countsthe wave pulses obtained with the D-PLL 32I explained in FIG. 7, andutilizes this count value. The shift amount (H) of the phase ispredetermined by the rotational speed of the rotor, and stored in amemory in a table format. The CPU depicted in FIG. 7 operates therotational speed of the rotor from the detection signal of the sensors34A, B, and determines the specific phase shift amount. Further, the CPUalso determines the dividing ratio (D) of the D-PLL 32I from the tablein accordance with the rotational speed of the rotor.

FIG. 17 is a detailed diagram of the A phase and B phase buffer circuits(32G, H) described above. This circuit includes switching transistorsTR1 to TR4 for applying exciting current formed of a wave pulse to the Aphase electromagnetic coil or B phase electromagnetic coil. Further, thecircuit also includes an inverter 35A.

Here, when “H” as the signal is applied to the buffer circuit, TR1 isturned off, TR2 is turned on, TR3 is turned on and TR4 is turned off,and the exciting current having an Ib direction is applied to the coil.Meanwhile, when “L” as the signal is applied to the buffer circuit, TR1is turned on, TR2 is turned off, TR3 is turned off and TR4 is turned on,and current having an Ia direction, which is opposite to Ib, is appliedto the coil. Therefore, the respective exciting patterns of the A phaseelectromagnetic coil and B phase electromagnetic coil may be alternatelychanged. This is as per the explanation made with respect to FIG. 1.

FIG. 18 is another embodiment thereof, and the portion differing fromthe driver unit 32 illustrated in FIG. 7 is in that a drive control unit300 is provided instead of the polarity switching unit and phasecorrection unit. This drive control unit is capable of performingrotation control to the A phase side coil and B phase side coil,respectively, and it is also capable of performing rotation control tothe coil only on one phase side.

As shown in FIG. 19, this drive control unit is structured from an Aphase coil, a B phase coil start-up control unit 30, and a sensorfollow-up control unit 304. The start-up control unit is for controllingthe start-up of the motor, and the sensor follow-up control unitimplements the operation for making the signal wave supplied to therespective phase coils follow and synchronize with the detected pulsefrom the respective phase sensors by returning such detected pulse,without having to supply a fundamental wave to the buffer unit after thestart-up of the motor. The frequency from the quartz oscillator 30 isdivided with the M-PLL 31, and this is supplied to the drive controlunit 300.

In FIG. 19, the rotation start/stop indication 306 and rotatingdirection indication 308 from the CPU 33 are input to the start-upcontrol unit 302 and the sensor follow-up control unit 304. Referencenumeral 310 is a multiplexer, and switches the control output from thestart-up control unit and the output from the sensor follow-up controlunit. The output (fundamental wave) from the D-PLL 32I is supplied tothe start-up control unit 302. With the multiplexer 310, a switchingcommand value for switching the output from the start-up control unit302 and the output (A phase drive, B phase drive) from the sensorfollow-up control unit 304 is output from the start-up control unit 302to the input terminal SEL of the multiplexer. The start-up control unit302 outputs to the multiplexer 310 and the sensor follow-up control unit304 the output Ti for converting the control mode from the post start-upcontrol phase to the sensor follow-up control phase. Moreover, theexciting current to be supplied to the start-up control unit during thestart-up of the motor may be a low frequency (for example, approximately10 Hz).

Reference numeral 312 is a PWM control unit, and the duty ratio of thedrive signal supplied to the respective coils based on the duty ratiocommand value 340 from the CPU 33 is changed. FIGS. 20(1) and (2) arewaveform characteristic charts in which the duty ratio has beencontrolled, and, with the H period of the respective drive outputs ofthe A phase and B phase, the duty ratio is changed under the control ofthe CPU. For instance, the duty ratio may be set to 100% at the timewhen maximum torque of the motor (load) is required (at the time ofstart-up, acceleration, and increase/variation in the load), and, inother cases; for example, during the running of the motor at a constantspeed or during a low load, the duty may be lowered. The CPU seeks theload fluctuation of the motor by measuring the sensor output from the Aphase side magnetic body and B phase side magnetic body, and determinesthe prescribed duty ratio from the table set and stored in the memory.The characteristic chart of (2), in comparison to the characteristicchart of (1), shows a control mode enabling the switching control of theduty ratio in a more favorable energy conversion efficiency.

FIG. 21 is a waveform characteristic chart in the circuit illustrated inFIG. 18; wherein (1) is the M-PLL wave pulse; (2) is the motor startflag; (3) is the A phase sensor output; (4) is the B phase sensoroutput; (5) is the flip-flop output based on the output of the A phasesensor; (6) is a flip-flop output based on the output of the B phasesensor; (7) is an output pulse waveform to the A phase coil; (8) is anoutput pulse waveform to the B phase coil; (9) is the start-up period ofthe motor; (10) is the count value of the counter corresponding to thestart-up period; and (1A) is a normal rotation/reverse rotation flag ofthe motor. The multiplexer depicted in FIG. 19 outputs the start-upcontrol unit 302 during the edge period of (9) above, and switches tothe sensor follow-up control unit 304 during the L period, and these areshown in (7) and (8).

Here, when the rotating direction and rotation indication are outputfrom the CPU to the start-up control unit 302 and the sensor follow-upcontrol unit 304, the start-up control unit raises a flag informing thestart-up period within the memory (c.f. FIG. 21(9)). The start-upcontrol unit 302 counts the wave pulse in an amount of 2π (for instance,a total of seven pulses) of the M-PLL 31. During this period ((10)),without having to follow the output from the sensor, as shown in FIG.21(7) and (8), the start-up control unit creates a drive signal based onthe frequency from the M-PLL in relation to the respective coils of theA phase and B phase, outputs this to the respective phase coils, andstarts up the motor. The start-up control unit resets the start-up flagafter the start-up period.

After the start-up period, the sensor follow-up control unit 304generates a drive signal to the respective phase coils from the outputof the respective phase sensors (FIG. 21(3), (4)) via the flip-flop(FIG. 21(5), (6)). During the sensor follow-up control period after thestart-up period, the sensor follow-up control unit 304 does not employthe output of the M-PLL for generating the drive signal to therespective phase coils. After the start-up period, the CPU outputs tothe multiplexer 310 a switching command to be sent to the sensorfollow-up circuit. The multiplexer switches the output from the start-upcontrol unit to an output from the sensor follow-up control unit, andoutputs this to the PWM control unit 312. At the PWM control unit, afterthe duty ratio of the drive output to the respective phase coils hasbeen changed and adjusted, or controlled, this is sent to the buffercircuits 32G, H of the respective phase coils. During a low rotation,since the respective phase sensors are not being used, an operation maybe employed for performing rotational speed control in which the M-PLLfrequency is changed only during the start-up period.

During the reverse rotation of the motor, when the reverse rotationcommand is made from the CPU to the start-up control unit or the sensorfollow-up control unit, a reverse rotation flag is raised (FIG. 21(1A)), the sensor follow-up control unit 304 once masks the output ofthe B phase sensor during the rotating direction displacement zoneperiod (reference numeral 350 in FIG. 22) after such flag is set, andswitches the polarity of the normal rotation exciting signal of the Bphase coil to the polarity of the B phase (during reverse rotation)during the masking. As a result, behavior of the motor from a normalrotation to a reverse rotation will become smooth. Or, a reverserotation flag may be set during a normal rotation, and a braking effectagainst the normal rotation can be obtained.

According to the embodiment described here, after the start of themotor, the drive control unit is able to supply the exciting signalcorresponding accurately to the load fluctuation of the motor since theexciting signal to be sent to the A phase magnetic body and B phasemagnetic body has been formed as a result of having followed the outputof the sensor. Further, when not much torque is required in the motor,after a steady rotation, A phase or B phase may be stopped. In such acase, the magnetic body of the phase in which the exciting signal hasbeen stopped may become a power generation means or braking controlmeans in a state other than an unexcited state.

FIG. 23 is a modified example of the exciting circuit (FIG. 14) forapplying exciting current to the electromagnetic coil, and differs inthat the sensor 34A is provided to only one phase side. In other words,the output frequency from the A phase sensor is N-multiplied at PLL2,and a simulation detected pulse frequency 34AB for controlling the Bphase coil is formed based on the foregoing clock. FIG. 24 is a controlwaveform characteristic chart of the circuit illustrated in FIG. 23, a Bphase coil control signal (3) is formed in accordance with the clockfrequency.

Next, FIG. 25 is a block diagram showing another embodiment of thestart-up control unit and sensor follow-up control unit depicted in FIG.19, and FIG. 26 is the control waveform timing chart thereof. Referencenumerals of the signal lines illustrated in FIG. 25 correspond to thereference numerals of the control waveform depicted in FIG. 25. FIG. 26shows the waveform of the signal lines with reference numerals.

Indication output (2) of the rotating direction from the CPU is outputto the EX-OR circuit 401 of the D input of the D flip-flop 400. Further,this output (2) is output to the TABLE 402 structured from a logiccircuit forming outputs (12) and (13) described later. The rotationstart indication output (3) and M-PLL clock (1) from the CPU are outputto the M value counter 404.

With the output value (8) of the M value counter, TABLE 402 and aprescribed N value are output to the recognition/identification circuit406. The foregoing rotation start support output (3) is also output tothe preset circuit 408 of the sensor value control unit. The A phasedrive start output (12) and B phase drive start output (13) from theTABLE 402 are output to the multiplexer 312. The A phase drive output(12) and B phase drive output (13) are output to the AB phase comparator410. Output from the AB phase comparator 410 is output to the Enableterminal of the D flip-flop 412. The Q output (11) of the D-FF 412 isoutput to the select termination of the multiplexer 312. The D input ofthe D-FF 412 is constantly excited to a level. The output (9) of theidentification circuit 406 is output to the AB phase comparing circuit.An A phase coil exciting signal is supplied from the multiplexer 312 tothe A phase buffer 32G. Similarly, a B phase coil exciting signal issupplied to the B phase buffer 32H. The output (11) of the Q terminal ofthe D-FF 412 is supplied to the M value counter 404. The output (11) issupplied to the preset circuit 408.

The position detection outputs (5) and (4) of the B phase sensor 34B andA phase sensor 34A are output to the NOR circuit 414. The output (5) isinput to the D-FF 400 clock. The output (4) is input to the D-FF 416clock. The output of the OR circuit 414 is supplied to the clock inputof the D-FF 412. The Q output (7) of the D-FF 400 is supplied to themultiplexer 312 and the AB phase comparing unit 410. The Q inverteroutput of the D-FF 416 is supplied to the D terminal. The Q output (6)of the D-FF 416 is supplied to the multiplexer 312 and the AB phasecomparing unit 410. The Q output of the D-FF 416 is supplied to theinput of the EX-OR circuit 401. Under the control of the CPU, the presetcircuit 408 supplies the preset output to the preset terminals of theD-FF 400, 416.

Next, the operation of the logic circuit block illustrated in FIG. 25 isexplained. This circuit forms A/B phase coil exciting signals (12) and(13) at the start of the motor with the start-up control unit, suppliesthis to the multiplexer, and supplies the exciting signal from themultiplexer to the A phase coil and B phase coil. Thereafter, when themotor starts to rotate, the A/B phase coil exciting signals synchronizedwith the A phase sensor and B phase sensor are formed at the sensorfollow-up control unit, and these are supplied to the respective phasecoils. Output of the start-up control unit and output of the sensorfollow-up control unit are switched with the switching signal (11) to besupplied to the select terminal (SEL) of the multiplexer, and thensupplied to the respective phase coils.

In accordance with the output (8) of the M value counter, the TABLE 402forms exciting signals (12) and (13) for exciting the respective phasecoils. The A phase coil and B phase coil to which the foregoing excitingsignal has been supplied rotates the rotor (reference numeral 14 of FIG.8) comprising a permanent magnet. When the rotor rotates, a detectionpulse is output from the A phase sensor and B phase sensor. When the Bphase sensor detects the rotation of the rotor and detects the positiondetection output (5), the NOR circuit 414 outputs a clock to the FF 412.When the A phase sensor detects the rotation of the rotor and generatesa position detection output (4), this is supplied to the clock input ofthe FF 416. When this clock is input, an A phase coil drive signal (6)is formed. The detected output of the B phase sensor is supplied to theFF 400, and a B phase coil drive signal (7) is created thereby.

When the count value of the counter becomes 2 or more, theidentification circuit 406 outputs an activation signal to the AB phasecomparing circuit 406. This based on the premise that while the countvalue of the counter is within three clocks, an H level pulse is outputfrom either the A phase sensor or B phase sensor. In the start-upperiod, since the exciting signals (12) and (13) are output, the ABphase comparing circuit 406 outputs an H level (10) to the ENABLEterminal of the FF 412. As a result, the FF 412 is activated, and, whenthe sensor side output is supplied to the clock input, supplied to themultiplexer 312 is a switching output (11) for switching the outputs(12) and (13) to be supplied to the coil to (6) and (7).

While receiving the input (H) of the output (11), the counter will notcount the new clock (1). Although the reset circuit 408 is controlledwith the CPU during the start-up period and supplies the preset outputto the FF 400 and 416, when the input of the signal (11) is at thepreset circuit, the preset state of the FF 400 and 416 will be released.

Next, another embodiment of the A phase coil drive buffer circuit and Bphase coil drive buffer circuit, different from FIG. 17, will beexplained with reference to FIG. 27. This embodiment differs from theone in FIG. 17 as follows. The A1 phase drive signal is supplied to thebuffer 600, the A2 phase drive signal is supplied to the buffer 602, theB1 phase drive signal is supplied to the buffer 604, and the B2 phasedrive signal is supplied to the buffer 606. The drive signal of therespective phases are supplied to the EX-NOR circuits 610, 614, and theoutput of this circuit is supplied to one terminal of the AND circuits(negative logic OR) 608, 612. Supplied to the other end of the ANDcircuits 608, 612 is the output of the OFF mode selection circuit 630.The output of the AND circuit is returned to the buffer. The selectioncircuit 630 is for selecting the OFF state (regenerative brake orinertia rotation) of the motor in a rotating state, and, in theregenerative brake state, an “L” level output is generated from theselection circuit with the CPU. In a stopped state, since the drivesignal of the respective phases is also an “L” level, the buffers, 600,602, 604, 606 are turned ON, the “L” signal is supplied to thetransistor on both sides of the A phase coil and B phase coil and becomea state of short circuit. Therefore, the motor is subject toregenerative braking, and may be utilized as a power generator.Meanwhile, when the motor selects “H”, these buffers are turned OFF,contact points at both ends of the coil become free, and the motor issubject to inertial rotation.

Next, another magnetic structure is explained. FIG. 28 is a view showingthe frame format and operational principle thereof. The first magneticbody 10 comprises a structure in which a plurality of coils 16 aredisposed in order in prescribed intervals, preferably in equalintervals. The plurality of coils is simultaneously excited to S or N.FIG. 29 is an equivalent circuit diagram of the first and secondmagnetic bodies. According to FIG. 28, as described later, every coil isconstantly excited during a single rotation (2π) in relation to thetwo-phase exciting coil. Therefore, a drive such as a rotor or slidermay be rotated or driven at high torque.

As shown in FIG. 29(1), a plurality of electromagnetic coils 16 or 18(magnetic units) is connected serially in equal intervals in the A phasecoil 10 and B phase coil 12, respectively. Reference numeral 18A is anexciting circuit block for applying a frequency pulse signal to thismagnetic coil. When an exciting signal for magnetizing the coil isflowed from this exciting circuit to the electromagnetic coils 16, 18,the coil group adjacent to the respective phases is structured to beexcited in a homopolar manner to S or N. As shown in FIG. 29(2), therespective electromagnetic coils (16 or 18) of the A phase coil 10 and Bphase coil 12 may also be connected in parallel.

When a signal having a frequency for alternately switching in prescribedcycles the polar direction of the exciting current to be supplied fromthis exciting circuit 18A to the electromagnetic coils 16, 18 of thefirst and second magnetic bodies 10, 12 as shown in FIG. 28, a magneticpattern is formed in which the polarity on the side of the thirdmagnetic body 14 alternately changes from the N pole→S pole→N pole. Thestructure of the second magnetic body 12 is similar to the firstmagnetic body 10, but differs in that the electromagnetic coil 18 of thesecond magnetic body is disposed positionally out of alignment (with anangular difference) in relation to the electromagnetic coil 16 of thefirst magnetic body.

In other words, the array pitch of the first magnetic body coil and thearray pitch of the second magnetic body coil are set to have aprescribed pitch difference (angular difference). As this pitchdifference, preferably employed may be a distance corresponding toπ/Nrad (where N is the number of permanent magnets).

Next, the operation of the magnetic structure in which the foregoingthird magnetic body 14 is disposed between the first magnetic body 10and the second magnetic body 12 is explained with reference to FIG. 28.As a result of the foregoing exciting circuit (reference numeral 18A inFIG. 29; described later), an exciting pattern as shown in FIG. 28(1) isgenerated to the electromagnetic coils 16, 18 of the first magnetic bodyand second magnetic body at a certain moment.

Here, a magnetic pole is generated in a pattern of all S poles to therespective coils 16 on the surface facing the third magnetic body 14side of the first magnetic body, and a magnetic pole is generated in apattern of all N poles to the coil 18 on the surface facing the thirdmagnetic body 14 side of the second magnetic body 12. In the diagrams,direction of the arrows represents the attraction and repulsion.Repulsion is generated between the same poles, and attraction isgenerated between the different poles.

The next moment, as a result of the balance of attraction and repulsionbetween the first/second magnetic bodies and the third magnetic body,the third magnetic body 14 moves toward the right of (1).

The next moment, when the respective coils of the first magnetic body 10are excited to the N pole and the respective coils of the secondmagnetic body 12 are excited to the S pole, as shown in (2) and (3), thethird magnetic body sequentially moves toward the right. Next, as shownin (4), when the magnetic pole of respective coils 16 of the firstmagnetic body 10 is magnetized to the S pole and the respective coils 18of the second magnetic body 12 are magnetized to the N pole, the thirdmagnetic body 14 moves further to the right. As a result of supplying arectangular wave having a phase capable of repeating (1) to (4) above tothe coil of the respective phases, it is possible to make the thirdmagnetic body 14 rotate or slide continuously.

That is, in the course of (1) to (4), the third magnetic body movesrelatively to the first/second magnetic bodies in a distancecorresponding to one cycle (2π) of the frequency signal supplied to theelectromagnetic coils 16, 18.

FIG. 30 is a diagram showing the materialization of the magneticstructure as a synchronous motor, wherein FIG. 30(1) is a perspectiveview of the motor; FIG. 30(2) is a schematic plan view of the rotor(third magnetic body); FIG. 30(3) is a side view thereof; FIG. 30(4)shows the A phase electromagnetic coil (first magnetic body); and FIG.30(5) shows the B phase electromagnetic coil (second magnetic body).Further, in order to better understand this structure, please refer tothe explanation of FIG. 8. As shown in FIGS. 30(2), (4) and (5), sixpermanent magnets are provided to the rotor in equal intervals aroundthe circumferential direction thereof. Polarities of the permanentmagnet are made to be mutually opposite, and six electromagnetic coilsare provided to the stator in equal intervals around the circumferentialdirection thereof.

The A phase sensor 34A and B phase sensor 34B are provided to thesidewall inside the case of the A phase magnetic body (first magneticbody) with an angular difference of π/2rad. Applied to the distancebetween the A phase sensor 34A and B phase sensor 34B is a distancecorresponding to a value for providing a prescribed phase difference tothe frequency signal supplied to the A phase coil 16 and the frequencysignal supplied to the B phase coil 18.

FIG. 31 is a signal waveform chart in an embodiment where the A phaseelectromagnetic coil and B phase electromagnetic coil are supplied witha two-phase drive signal, respectively, in the structure of FIG. 28 andFIG. 29. The waveform of the first phase (A1 phase drive) and thewaveform of the second phase (A2 phase drive) of the A sideelectromagnetic coil have a phase difference of π.

The waveform of the first phase (B1 phase drive) and the waveform of thesecond phase (B2 phase drive) of the B side electromagnetic coil alsohave a similar phase difference. The phase difference between the Aphase drive signal and the B phase drive signal waveform is π/2. As aresult of two-phase driving the A phase side magnetic body and the Bphase side magnetic body, respectively, the drive torque of the motorcan be increased.

FIG. 32 is a diagram showing the buffer circuit for two-phase drivingthe A phase magnetic body and the B phase magnetic body. In addition,although the sensor explained above was an optical hole sensor, this mayalso be a magnetic sensor. Further, although the holes were providedbetween the permanent magnets, the holes may also be provided to thepermanent magnet points. In such a case, the position of the A/B phasesensor will be reversed.

FIG. 33 is a modified example of the motor illustrated in FIG. 8. (1) isa plan view thereof, and (2) is a side view thereof. The motor depictedhere differs from the motor illustrated in FIG. 8 with respect to thepoint that the first magnetic body 10, second magnetic b body 12 andthird magnetic body 14 are mutually facing each other along the radialdirection.

Further, the electromagnetic coil 16 of the first magnetic body 10 andthe electromagnetic coil 16 of the second magnetic body 12 are disposedso as to mutually have an array pitch difference B. The third magneticbody 14 has a cross section in the radial direction of an approximate Ushape, a circular area 14B forming the side face is interpositionedbetween the first magnetic body 10 and the second magnetic body 12, andthe permanent magnet 18 is disposed evenly along the circumferentialdirection thereof.

FIG. 34 is a view showing the frame format of the linear motor formedwith the magnetic structure according to the present invention. (1) and(2) are diagrams showing the third magnetic body 14 as the slider, andthe main body 102 including the first and second magnetic bodies 10, 12as the stator, wherein (1) is the front view thereof, and (2) is theside view thereof. Further, (3) and (4) are diagrams showing the thirdmagnetic body 14 as the stator, and the foregoing main body 102 as theslider, wherein (3) is the front view thereof, and (4) is the side viewthereof. Reference numeral 100 is a bearing.

FIG. 35 is a view showing the frame format of a motor pertaining to yetanother embodiment. This motor differs from the motors described abovein that a plurality of rotors 14 is connected serially. In other words,via the partition board 110, two magnetic structures are laminatedserially along the rotational axis 14A direction of the motor. Thefollowing magnetic structure comprises a pair of magnetic bodies 10, 12to become the stator, and a rotor 14 formed by disposing a plurality ofpermanent magnets in the circumferential direction between the stators.The rotational axis 14A is axially supported in the housing 114 with thebearing 112. According to the present embodiment, in addition to thegenerated torque being doubled, there is an advantage of being able toprovide a motor capable of high rotation. Further, the respectivemagnetic bodies 10, 12 at both ends of the partition board 110 may alsobe shared as a single magnetic body.

FIG. 36 is a diagram for explaining a motor pertaining to yet anotherembodiment, and differs from the foregoing embodiments in that a gear120 has been formed in the rotor, wherein (1) is the plan view thereof,and (2) is the side view thereof. As shown in (1), a gear 120 is formedat the peripheral edge of the rotor 14. The permanent magnet 18 isprovided in even intervals in the circumferential direction of the rotorformed in a circular arc. FIG. 37 is a modified example of the rotorillustrated in FIG. 14, wherein (1) is a plan view thereof, and (2) is aside view thereof.

A hollow boss portion 124 having a prescribed diameter is provided fromthe center of the rotor 14 in the radial direction, and a gear 120protruding toward the center direction of the motor is formed in thecircumferential direction of this cavity. According to this structure,there is an advantage in being able to convey motive energy to thetransmission mechanism on the side subject to a direct load.

FIG. 38 is a diagram showing that, when the motor is used as the powergenerator, an alternate voltage output waveform independent from the Aphase/B phase electromagnetic coil thereof can be obtained. As a resultof employing the function of this power generator, the A phase and Bphase may be independently and easily subject to regenerative brakingand braking control. Moreover, although the foregoing explanation wasmade by exciting and driving both electromagnetic coils of the A phaseand B phase, during a light torque after the drive, a drive pursuant toa low-power mode by exciting the phase on only one side of either the Aphase or B phase may also be adopted.

FIG. 39 is a view showing the frame format pertaining to the structureof a motor in which the displacement of the stator 10 formed with thefirst magnetic body and the stator 12 formed with the second magneticbody differs from the displacement illustrated in FIG. 33, wherein FIG.39(1) is a plan view thereof; and FIG. 39(2) is an A-A cross sectionthereof.

In the foregoing embodiment (FIG. 33), a rotor structure was illustratedwhere two stators were made to mutually face each other along the radialdirection, and a rotor 14 having a plurality of permanent magnets wasdisposed between the two stators. Meanwhile, with the motor depicted inFIG. 39, the two stators are positioned out of alignment along therotational axis 14A of the motor, and a rotor having a smaller diameterthan such stators is disposed between these stators.

Here, the two stators 10, 12 are located on the outer peripheral sidealong the radial direction of the rotor 14, and the electromagnetic coil14 in the first stator and the electromagnetic coil 16 in the secondstator are disposed having a phase difference (pitch difference)corresponding to π/2 of the exciting signal as described above.

As a result of supplying a frequency signal having mutually differentphases to the two stators structured as above, the rotor may be rotatedin a prescribed direction. Here, the magnetic force direction of thestationary part (stator) in relation to the magnetic force direction ofthe rotator (rotor) will magnetically intersect perpendicularly.Further, reference numeral 200 is the outer frame of the rotor, and 202is a bearing for rotatably supporting the rotational axis 14A with theouter frame 200.

In addition, as the material for structuring the case, stator or rotor,a non-magnetic body (resin, carbon, glass, aluminum, magnesium, or acombination thereof) is preferable, but may be suitably selected inconsideration of the required intensity. Further, since the line ofmagnetic force will discharged outside when using a non-magnetic bodycase, it would be preferable to suppress the line of magnetic force frombeing discharged outside by forming the case with a magnetic bodymaterial, or covering the case with a coating material containing amagnetic body.

FIG. 40 is a plan view showing another embodiment of the rotor 14, andthe permanent magnet 14 may be structured such that the magnetic body isexcited in a multipolar manner. Reference numeral 14-1 is the centermaterial of the rotor, and may be a non-magnetic body such as resin.Reference numeral 14-2 is a magnetic body formed around the centermaterial, and is alternately magnetized to opposite poles. Referencenumeral 14-3 is the rotor axis. By structuring the center material 14-1with a material other than a magnetic body, the rotor can be made lightand thin. Since the heavy load of the permanent magnet is disposedaround the rotor 14, when this is rotated at high speed, the rotor mayfunction for gyro control or as a gyro sensor. This may be used in theequilibrium control of robots, helicopters, airplanes, vehicles, and soon.

FIG. 41 is a conceptual diagram of the torque calculation of the rotor.When the start-up torque is Fst[g·cm], torque radius is R[cm],attraction of the permanent magnet and coil is Fx[g], number ofpermanent magnets is N, and number of phases (A phase, B phase, etc.) isA, Fst=R*Fx*N*A[g·cm].

FIG. 42 is a diagram showing another embodiment of the magneticstructure. The rotor to rotate around the axis 14-3 is formed not in acircuit, but in a fan shape. Mutually heteropolar permanent magnets 14-2are embedded in the fan shaped rotating body 14-1. A pole shaped member14-5 is mounted radially from the fan shaped rotating body 14-1 so as toprotrude outside the case. When the fan shaped rotating body rotates,the pole shaped member conducts a reciprocating motion in the arrowdirection. As shown in FIG. 35(2), the fan shaped rotating body 14-1 issandwiched between the A phase electromagnetic coil 10 and the B phaseelectromagnetic coil 12, and, by flowing the foregoing frequency signalto the A phase and B phase, it is possible to rotate the fan shapedrotating body in a prescribed direction.

FIG. 43 is a modified example of the embodiment shown in FIG. 35. Axes360A, 360B are separated in the middle thereof, and the respective axesmay be separately rotated with their respective magnetic structures. Therespective axes are subject to rotational control by a pair of rotors 14formed from the A phase coil 10, B phase coil 12 and permanent magnet.The end portion of the axis inside the motor is connected to the bearing362, and rotatably supports the respective axes 360A, 360B individuallysuch that the respective axes can be rotated in different directions orat different speeds, respectively. Reference numerals 364, 366 arebearings for rotatably supporting their respective axes. A frequencysignal of the A2 phase and B1 phase is supplied to one pair among thetwo pairs of magnetic structures, and a frequency signal of the A2 phaseand B2 phase is supplied to the other pair.

FIG. 44 is another modified example, and a cavity is formed in the axis360A. Another axis 360B is penetrating this axis. Axes 360A and 360B arerespectively subject to rotational control under separate pairs ofmagnetic bodies.

FIG. 45(1) shows an embodiment employing the magnetic structure of thepresent invention for driving a lens. This is an electromagnetic coilformed from reference numerals 10, 12 and the A phase and B phase, and amultipolar exciting type permanent magnet rotor 14 shown in FIG. 42(2)is disposed between the electromagnetic coils. Reference numeral 380 isa gear unit, and converts the rotor rotation into a linear reciprocatingmotion shown with the arrow. Reference numeral 382 of (1) is an insidegear for engaging with the foregoing gear. When rotor 14 is rotated, thelens unit 388 comprising the lens 386 retreats in the arrow direction,and, for example, the focus distance may be changed.

FIG. 46(1) is a diagram showing an embodiment where the rotor of themagnetic body is flexible. A plurality of permanent magnets 390 isprovided by being embedded in rows along the longitudinal direction ofthe viscous body (including the caterpillar) 392 that is flexible anddeformable. As shown in (2), which is the B-B′ cross section of (1),this viscous body has a oval and circular T-shaped cross section, theinside thereof is a bearing or oil lubricant 394, and is supported suchthat it may be driven in circles against the key-shaped fixed portion396. Reference numeral 398 is a pair of A phase/B phase coils. Sincethis viscous body can be driven like a caterpillar, for example, thismagnetic body may be employed as a caterpillar of moving vehicles. (3)is the side view in the A-A′ direction.

FIG. 47 is a modified example of FIG. 46. (1) is a plan view, (2) is thecross section in the A-A direction, and (3) is the cross section in theB-B direction. The viscous body (deformable) is in an approximate ovalshape, has an approximate T-shaped cross section, has bearing oil at thetip, and a permanent magnet is provided in the middle thereof. Aplurality of permanent magnets is provided along the length direction ofthe viscous body. The fixed portion 396 has an approximate oval shape,and the viscous body is capable of circulating while deforming to theshape of such fixed portion.

FIG. 48 is a diagram showing the power generation circuit employing themagnetic structure described above. FIG. 48(1) is for supplying thegenerated electromotive force of the A phase coil and the generatedelectromotive force of the B phase coil to the respective independentload circuits; (2) is for supplying the coil generated electromotiveforce of the respective phases to the common load circuit, and (3) isfor serially connecting the A phase coil and B phase coil and supplyingthe generated electromotive force to the power generation circuit.Further, the power generation for realizing the foregoing magneticstructure is broad, and, in addition to wind power and wave power, powergeneration by regenerative braking against the moving vehicle may alsobe employed.

FIG. 50 is a principle diagram showing the power generation principle. Aplurality of magnetic elements 913 alternately charged to opposite polesis disposed to the foregoing rotor or slider (914). A magnetic fieldshown with an arrow in the diagram is generating between these magneticelements. When this rotor 914 and coils 910, 912 move relatively, themagnetic field intensity to the respective coils will change each timeit passes through the magnetic element 913, and, as a result, asinusoidal electromotive force without any distortion as shown in 916and 918 is generated. As a result, Bh(T): horizontal magnetic fluxdensity (coil center) and CL (coil length); and P(m/s): Eac(electromotive force) corresponding to the product with the moving speedof coil are obtained.

In FIG. 50, a plurality of permanent magnets 913 is alternately disposedso as to be opposite poles along the circumferential direction of therotor 914. Therefore, magnetic poles exist parallel or horizontal in therotational direction (moving direction) of the rotor. As a result, bysupplying exciting current having a frequency to the coil, the rotorwill rotate in the circumferential direction. Further, during powergeneration, the strength of the magnetic field affecting the coil willperiodically change pursuant to the magnetic field of the rotor, and theback electromotive force described above is generated in the coil. Thetraveling energy is changed to electric energy with a discoid rotor anda coil also formed in a disk, and this may be used as the driving forcefor starting or accelerating upon moving the driver.

Further, in the embodiments described above, although the outer shape ofthe rotor and electromagnet was illustrated in a circle, the shape isnot limited thereto, and any rotatable shape, such as oval or the like,may also be employed.

The structure explained in the foregoing embodiments may be suitablymodified within the range of the technical spirit of the presentinvention. For example, in the foregoing embodiment, although the numberof holes 35 illustrated in FIG. 8 was equivalent to the number ofpermanent magnets (or this number was limited to one hole), the numberis not limited thereto. In the foregoing embodiment, although an opticaltype and magnetic type were used as the sensor, the back electromotiveforce generated in the coil may also be used as the detection signal. Insuch a case, the coil itself will concurrently function as the sensor.Further, with the magnetic structure shown in FIG. 50 and FIGS. 1 to 4,shorter the distance between the permanent magnets, higher thehorizontal magnetic flux density B(h).

1. A motor comprising: a first magnetic body; a second magnetic body;and a third magnetic body disposed between said first and secondmagnetic bodies, the third magnetic body being relatively movable in aprescribed direction in relation to said first and second magneticbodies, wherein said first magnetic body and second magnetic bodyrespectively comprise a structure in which a plurality ofelectromagnetic coils capable of being alternately excited to oppositepolarities is disposed in order; said third magnetic body comprises astructure in which permanent magnets alternately magnetized to oppositepolarities are disposed in order; and said first magnetic body and saidsecond magnetic body are structured such that an electromagnetic coil ofsaid first magnetic body and an electromagnetic coil of said secondmagnetic body are disposed so as to mutually possess an array pitchdifference, said magnetic structure further comprising a coil excitingcircuit for supplying an exciting current including frequency signalshaving different phases to the electromagnetic coils of said first andsecond magnetic bodies, wherein the pair formed from said first andsecond magnetic bodies and one side of said third magnetic body form arotor, and the pair formed from said first and second magnetic bodiesand the other side of said third magnetic body form a stator, wherein anequal number of magnet poles of the rotor and poles of theelectromagnetic coil for the phase are formed, wherein the rotor isformed from a nonmagnetic material disc and a plurality ofelectromagnetic coils or permanent magnets, a rotation speed detectorthat detects the rotation speed of the rotor being set in a directionperpendicular to an axis of the rotor, and wherein said coil excitingcircuit controls excitation of the electromagnetic coils of said firstand second magnetic body via the exciting current supplied to theelectromagnetic coils, the phase of the current being corrected based ona rotational speed of said rotor.
 2. A motor according to claim 1,wherein said first magnetic body, second magnetic body and thirdmagnetic body are respectively formed in a circular arc.
 3. A motoraccording to claim 2, wherein said first magnetic body and secondmagnetic body are disposed at an equidistance, and said third magneticbody is disposed between said first magnetic body and second magneticbody.
 4. A motor according to claim 3, wherein the pair formed from saidfirst and second magnetic bodies and one side of said third magneticbody form a slider, and the pair formed from said first and secondmagnetic bodies and the other side of said third magnetic body form astator.
 5. A motor according to claim 1, wherein said first magneticbody, second magnetic body and third magnetic body are respectivelyformed in a straight line.
 6. A motor according to claim 1, wherein saidcoil exciting circuit comprises a reference pulse signal generator; anda phase corrector that corrects the phase of the exciting current to besupplied to the electromagnetic coil of said first magnetic body and theelectromagnetic coil of said second magnetic body based on saidrotational speed detection signal and said reference pulse signal.
 7. Amotor according to claim 6, wherein said coil exciting circuit comprisesa buffer that controls an exciting direction of said electromagneticcoil at a prescribed duty ratio upon the phase-corrected excitingcurrent being supplied thereto.
 8. A motor according to claim 1, whereina gear is formed on said rotor.
 9. A motor according to claim 1, whereinsaid rotor is connected to a rotating body, and functions as a powergenerator.
 10. A motor according to claim 1, wherein a plurality ofpairs formed from said stator and rotor is connected serially or inparallel.
 11. A driver comprising the motor according to claim 1 as adrive source.
 12. A motor according to claim 1, wherein said coilexciting circuit comprises a start-up control unit for generating areference wave pulse and forming an exciting signal to be supplied tosaid magnetic body from said reference wave pulse in order to start-upsaid first and/or second magnetic body; and a sensor follow-up controlunit for forming an exciting signal to be supplied to said magnetic bodyby following the output from the rotational position sensor of saidmagnetic body after the start-up of said magnetic body.
 13. A motoraccording to claims 1, wherein every exciting coil is constantly excitedduring the start-up rotation (2π) in relation to the two-phase excitingcoil.
 14. A motor according to claim 1, wherein the duty ratio of thesignal to be supplied from said coil exciting circuit to theelectromagnetic coil of said first and/or second magnetic body is madeto change.
 15. A motor according to claim 14, wherein said duty ratio isdetermined in accordance with the driving state of the load driven withsaid magnetic structure.
 16. A motor according to claim 1, wherein saidfirst and second magnetic structures are structured from anelectromagnetic coil formed in a coil shape by winding a conductingsleeve around a nonmagnetic bobbin.
 17. A motor according to claim 16,wherein a magnetic body is driven via switching of attraction andrepulsion between third magnetic bodies formed from said electromagneticcoil and a permanent magnet.
 18. A motor according to claim 16, whereinsaid first and second magnetic bodies are structured from a magneticstator formed from a nonmagnetic bobbin.
 19. A motor comprising: a firstmagnetic body; a second magnetic body; and a third magnetic bodydisposed between said first and second magnetic bodies, the thirdmagnetic body being relatively movable in a prescribed direction inrelation to said first and second magnetic bodies, wherein said firstmagnetic body and second magnetic body respectively comprise a structurein which a plurality of electromagnetic coils capable of beingalternately excited to opposite polarities is disposed in order; saidthird magnetic body comprises a structure in which permanent magnetsalternately magnetized to opposite polarities are disposed in order; andsaid first magnetic body and said second magnetic body are structuredsuch that an electromagnetic coil of said first magnetic body and anelectromagnetic coil of said second magnetic body are disposed so as tomutually possess an array pitch difference, said magnetic structurefurther comprising a coil exciting circuit for supplying an excitingcurrent, including frequency signals having different phases to theelectromagnetic coils of said first and second magnetic bodies, whereinthe pair formed from said first and second magnetic bodies and one sideof said third magnetic body form a rotor, and the pair formed from saidfirst and second magnetic bodies and the other side of said thirdmagnetic body form a stator, wherein an equal number of magnet poles ofthe rotor and poles of the electromagnetic coil for the phase areformed, wherein a gear is formed on said rotor or stator, wherein therotor is formed from a nonmagnetic material disc and a plurality ofelectromagnetic coils or permanent magnets, a rotation speed detectorthat detects the rotation speed of the rotor being set in a directionperpendicular to an axis of the rotor, and wherein said coil excitingcircuit controls excitation of the electromagnetic coils of said firstand second magnetic body via the exciting current supplied to theelectromagnetic coils, the phase of the current being corrected based ona rotational speed of said rotor.